JP7474941B2 - Belt press filter cloth folding method - Google Patents

Description

The present invention relates to a method for folding filter cloth in a belt press that aims to extend the life of the filter cloth by shifting the position of the folds formed in the width direction of an endless filter cloth that is freely wrapped around the belt press.

Conventionally, a belt press is known in which two endless filter cloths are freely moved around multiple rollers, and sludge sandwiched in the filtration space formed between the two filter cloths is dewatered by the tension of the filter cloths and the squeezing force of the pressure rollers.

Patent Document 1 discloses a belt press in which both ends of an upper filter cloth and a lower filter cloth that make up two endless filter cloths are overlapped and folded back to form a filtration space between the upper and lower filter cloths.

In addition, Patent Documents 2 and 3 disclose a belt press in which a single endless filter cloth is folded back in the width direction to form a filtration space.

Patent No. 6164534 Patent No. 6233715 JP 2016-073928 A

Conventionally, belt presses using two endless filter cloths have two filter cloths stacked on top of each other to form a filtration space. However, this is a configuration in which the filter cloths are simply stacked one on top of the other, and the mating surfaces of the filter cloths have low sealing properties, resulting in a side leak phenomenon in which sludge flows out from the mating surfaces of the filter cloths when pressure is applied due to external pressure.

Patent Document 1 discloses a belt press in which overlapping upper and lower filter cloths are folded back from both sides in the width direction toward the sludge supply side to form a filtration space in order to prevent side leaks. However, because it was necessary to repeatedly fold and unfold the filter cloth while operating, stress was concentrated at the folded parts. This caused problems with breakage at the folded parts, leading to breakage of the filter cloth. In particular, repeated folding and unfolding at the folded parts formed at the position where they intersect with the filter cloth joints, which are made by overlapping and sewing the free ends together, caused stress to concentrate at the sewn parts, leading to wear at the sewn parts and early breakage of the filter cloth. Because breakage of the filter cloth occurred frequently, it was necessary to repair or replace the filter cloth each time. Since it was necessary to stop operation during repairs and replacement, there was also the issue of long downtimes.

The belt presses in Patent Documents 2 and 3 also form a filtration space by folding the filter cloth from both sides in the width direction toward the sludge supply side, which causes stress to concentrate on the folds formed at both ends of the filtration space, resulting in the problem of the filter cloth breaking early. Because the filter cloth breaks in a short period of time, it is necessary to frequently repair or replace the filter cloth, which is time-consuming and costly.

In addition, Patent Documents 2 and 3 state that various filtering spaces can be formed by shifting the position of the folded parts of the filter cloth, but there is no mention or suggestion that the purpose of shifting the position of the folded parts is to disperse the stress acting on the folded parts and extend the life of the filter cloth.

The present invention provides a method for folding filter cloth in a belt press that disperses the stress on the folded portion by shifting the position of the folded portion formed in the width direction of the endless filter cloth, thereby preventing early tearing of the filter cloth.

In a belt press that performs a sludge supplying process in which sludge is supplied onto an endless filter cloth that is freely moved around a number of rollers, a filter cloth folding process in which the filter cloth is folded back from both sides in the width direction toward the supply side and the folded back filter cloths are overlapped to form a filtration space, a squeezing filtration process in which the sludge in the filtration space is squeezed and filtered, a filter cloth unfolding process in which the folded back filter cloth is unfolded, and a cake peeling process in which a cake is peeled off from the unfolded filter cloth, the filter cloth is guided to the folding device that has been moved a predetermined width in the filter cloth folding process, and the position of the folds formed at both ends of the filtration space is shifted, thereby preventing stress from concentrating on the folds that are repeatedly folded and unfolded.

The filter cloth folding process can shift the position of the fold formed in the filter cloth by oscillating a folding device having a pressure roller, a guide roller, and a guide portion in the width direction of the filter cloth.

The folding device can be swung in the width direction of the filter cloth by being attached to a moving mechanism having a swinging part that can swing in the width direction of the filter cloth.

According to this invention, the folding device can be forcibly swung in the width direction to move it a predetermined width in any direction, thereby shifting the position of the folds formed in the width direction of the filter cloth. By shifting the position of the folds, the stress acting on the folds due to the folding and unfolding of the filter cloth can be dispersed, and the life of the filter cloth can be extended. This eliminates the need to frequently repair and replace the filter cloth, and eliminates the effort and cost of replacing the filter cloth. Operation downtime due to repairs and replacement is also shortened, and efficient continuous dehydration operation can be performed.

FIG. 1 is a schematic side view of a belt press according to the present invention. FIG. 13 is a development view of the filter cloth folded by the folding device. FIG. 4 is a cross-sectional view of the filter cloth folded by the folding device. FIG. FIG. FIG. FIG. FIG. 4 is a schematic perspective view of a moving mechanism of the folding device according to the first embodiment; FIG. 11 is a plan view for explaining a folding position shifting step S2 according to the embodiment of the present invention. FIG. 11 is a plan view illustrating the folding position shifting step S2. FIG. 11 is a plan view illustrating the folding position shifting step S2. FIG. 11 is a plan view illustrating the folding position shifting step S2.

FIG. 1 is a schematic side view of a belt press according to the present invention.
The belt press 1 of the present invention comprises a plurality of rollers 2..., endless upper and lower filter cloths 3a and 3b that are wrapped around the plurality of rollers 2... and are allowed to run freely, a hopper 4 that supplies sludge onto the lower filter cloth 3b, a folding device 6 that folds the lower filter cloth 3b from both sides in the width direction toward the sludge supply side and overlaps the folded lower filter cloth 3b and upper filter cloth 3a to form a filtration space 5 shown in the latter part, a shear roll 7 around which the lower filter cloth 3b and upper filter cloth 3a that have formed the filtration space 5 are wound, a spreading device 8 that spreads out the folded lower filter cloth 3b and upper filter cloth 3a, peeling rollers 9, 9 that peel off cakes from each of the spread filter cloths 3, and a guide roller 33 that guides the lower filter cloth 3b, which returns after passing through the peeling roller 9, to the folding device 6.

The endless lower filter cloth 3b, which is wrapped around multiple rollers 2..., has both ends in the width direction folded back by the folding device 6. The folding device 6 supplies sludge from the hopper 4 while folding both ends of the lower filter cloth 3b in the traveling direction (vertical direction) so that the endless lower filter cloth 3b can receive the sludge. Therefore, during the folding process, both ends of the lower filter cloth 3b are folded, and sludge is supplied onto the lower filter cloth 3b when the cross section of the lower filter cloth 3b becomes U-shaped. After the sludge is supplied, the upper filter cloth 3a is guided by the pressure roller 12a and made to run so as to cover the sludge supplied to the lower filter cloth 3b.

The lower filter cloth 3b and the upper filter cloth 3a are folded back at both ends in the width direction by a folding device 6 to form a filtration space 5. The lower filter cloth 3b and the upper filter cloth 3a, which have been supplied with sludge in the filtration space 5, are wrapped around a shear roll 7 to squeeze and filter the sludge. After squeezing and filtering, the lower filter cloth 3b and the upper filter cloth 3a are each spread out by a spreading device 8, and the cake peeled off by peeling rollers 9, 9 is discharged to the outside.

FIG. 2 is a development view of the filter cloth folded by the folding device according to the present invention.
The filter cloth 3 is folded back at arbitrary positions from both sides in the width direction toward the sludge supply side. Folded portion 10a is formed by folding back an arbitrary distance t1 from the left end of the filter cloth 3 toward the supply side in the traveling direction. Folded portion 10b is formed by folding back an arbitrary distance t2 from the right end of the filter cloth 3 toward the supply side in the traveling direction. The folded surface when the filter cloth 3 is folded back from the left side is designated as 11a, and the folded surface when the filter cloth 3 is folded back from the right side is designated as 11b.
In addition, since both the endless upper filter cloth 3a and the endless lower filter cloth 3a are folded back in the same manner, the filter cloth 3 refers to either the upper filter cloth 3a or the lower filter cloth 3.

FIG. 3 is a cross-sectional view of a filter cloth folded by a folding device according to the present invention.
As shown in Fig. 3(a) , the upper filter cloth 3a and the lower filter cloth 3b are overlapped and folded back from both sides in the width direction toward the supply side to form the filtration space 5. The occurrence of side leaks is prevented by forming folds 10a and 10b at both ends in the width direction of the filtration space 5, which is deformed by external pressure.

The folded surfaces 11a and 11b of the lower filter cloth 3b overlap with the corresponding folded surfaces 11a and 11b of the upper filter cloth 3a, thereby sealing the filtration space 5. To improve the sealing performance, it is sufficient to increase the overlapping area of the folded surfaces 11a and 11b of the upper filter cloth 3a and the lower filter cloth 3b. The sealing performance can also be improved by further folding back the overlapping areas of the folded surfaces 11a and 11b of the upper filter cloth 3a and the lower filter cloth 3b.

The distances t1 and t2 by which the folded portions 11a and 11b are folded back from both sides may be the same or different. As shown in Fig. 3(b), the upper filter cloth 3a having the same width as the distance between the two folded portions 10a and 10b may be guided above the sludge, or as shown in Fig. 3(c), the upper filter cloth 3a may be guided to the upper surfaces of the folded surfaces 11a and 11b of the folded lower filter cloth 3b.
In this embodiment, the belt press has two endless filter cloths, but it may have one endless filter cloth.

4 and 5 are a plan view and a side view, respectively, of the device for folding a filter cloth according to the present invention.
The folding device 6 is composed of a pressure roller 12b that presses the lower filter cloth 3b from above to form a U-shaped bottom, a guide roller 13 that folds the lower filter cloth 3b from both sides in the width direction to form the sides of the U-shape, guide parts 14a, 14b that horizontally guide the folded surfaces 11a, 11b of the folded lower filter cloth 3b, and a pressure roller 12a that presses the upper filter cloth 3a while guiding it from above. A hopper 4 is provided at a position where sludge can be supplied into the lower filter cloth 3b folded into the U-shape.

The lower filter cloth 3b, which is folded by the folding device 6, is formed into a U-shape by the pressing roller 12b so that sludge does not leak out. The width of the pressing roller 12b is equal to the folded width of the lower filter cloth 3b, and the pressing roller 12b presses the center of the upper surface of the lower filter cloth 3b downward to form the lower filter cloth 3b into a U-shape. Therefore, the pressing roller 12b forms the bottom of the U-shape.

At the same time, both ends of the lower filter cloth 3b are folded by guide rollers 13 arranged vertically on both sides of the pressure roller 12b, forming U-shaped sides. Downstream of the pressure roller 12b, a hopper 4 for supplying sludge hangs down toward the traveling lower filter cloth 3b, supplying sludge continuously. Downstream of the hopper 4, the upper filter cloth 3a is guided above the sludge by the pressure roller 12a, and the sludge is sandwiched between the upper filter cloth 3a and the lower filter cloth 3b.

The lower filter cloth 3b, whose both sides are gradually folded into a U-shape along the guide roller 13, is folded inward by a number of guide parts 14a, 14b fixed horizontally downstream of the positions of the hopper 4 and the pressure roller 16a. At this time, the upper filter cloth 3a is guided into the recess of the U-shaped lower filter cloth 3b, and when the lower filter cloth 3b is folded back, both ends of the lower filter cloth 3b are folded back so as to sandwich the upper filter cloth 3a.

One vertical side edge of the lower filter cloth 3b is guided to be folded horizontally at the bottom of the guide section 14a, and the other vertical side edge of the lower filter cloth 3b is similarly guided to be folded horizontally at the bottom of the guide section 14b. As both sides of the vertical lower filter cloth 3b are folded inward and become horizontal, the lower filter cloth 3b is folded back as it travels, enveloping the sludge and the upper filter cloth 3a that has been guided above the sludge inside.

If the auxiliary part 17 is disposed horizontally on the bottom of the filter cloth 3 where the guide parts 14a, 14b come into contact, the filter cloth 3 will not bend due to the pressure of the guide parts 14a, 14b, and no misalignment will occur when the filter cloth 3 is folded in thirds. The guide parts 14 and the auxiliary part 17 are rod-shaped, plate-shaped, or the like.
In this embodiment, the guide portions 14 are disposed on both sides of the filter cloth 3, but a common guide portion may be used to press the filter cloth 3. The shape, material, number, and arrangement of the guide portions 14 may be appropriately selected.

6 and 7 are plan and side views, respectively, of a deployment apparatus according to the present invention.
The belt press 1, in which the filter cloth 3 is folded back to form the filtration space 5, is provided with an unfolding device 8 that unfolds the filter cloth 3 forming the filtration space 5 on the downstream side of the shear roll 7 in order to discharge the dehydrated cake inside.

The unfolding device 8 is composed of a straightening roller 18 arranged after the shear roll 7, and an unfolding guide 19 that guides the unfolding of the filter cloth 3. If the unfolded filter cloth 3 is about to bend again, an auxiliary guide 20 that holds the unfolded filter cloth 3 may be arranged after the unfolding guide 19. After the unfolding device 8, a peeling roller 9 is provided around which the unfolded filter cloth 3 is wrapped.

The straightening rollers 18 are arranged after the shear rolls 7 to prevent the tension trying to unfold the filter cloth 3 from influencing the shear rolls 7 and affecting the filter cloth running. The straightening rollers 18 are arranged rotatably at both ends of the width of the filter cloth 3 transferred from the shear rolls, and the filter cloth 3 runs against the straightening rollers 18, which can guide the filter cloth 3 so that it does not unfold beyond a U-shape when it begins to unfold. Therefore, the tension trying to unfold the filter cloth 3 is not directly transmitted to the shear rolls 7, and the filter cloth 3 does not unfold on the shear rolls 7.

The unfolding guides 19 used in this embodiment are two long plates. The unfolding guides 19 are arranged on the inside of the folded filter cloth 3, downstream of the correction roller 18, and guide the filter cloth 3 so that it spreads out to the left and right.

Specifically, two unfolding guides 19 are disposed in a V-shape on the filter cloth 3 so as to unfold from the upstream side to the downstream side of the filter cloth 3. The unfolding guides 19 are bent at both ends of the filter cloth 3 and are provided extending downward and outward from the filter cloth 3. By disposing the unfolding guides 19 in this manner, the filter cloth 3 unfolds along the unfolding guides 19, and both ends of the filter cloth 3 are caught at the bent portions of the unfolding guides 19, allowing the filter cloth 3 to unfold completely.
In this embodiment, two unfolding guides 19 are provided, but a plurality of reinforcing ribs or the like may be provided in the width direction between the unfolding guides 19, 19 to connect them together into an integrated structure.

Also, auxiliary guides 20 may be arranged on both ends of the filter cloth 3 located downstream of the unfolding guide 19. The filter cloth 3 unfolded by the unfolding guide will tend to bend inward again due to tension concentrated in the center of the filter cloth 3. Therefore, auxiliary guides 20 are arranged to sandwich the filter cloth 3 from above and below, and guide the unfolded filter cloth 3 so that it does not bend. If the auxiliary guides 20 are arranged with an outward inclination toward the traveling direction of the filter cloth 3, they will follow the unfolding of the filter cloth 3, and can be guided without placing a load on the filter cloth 3.

The filter cloth 3 is spread by the spreading device 8, and the cake generated in the filtration space 5 of the traveling filter cloth 3 is discharged. The cake discharged by the spreading device 8 is peeled off by peeling rollers 9, 9 downstream of the spreading device 8, and then discharged to the outside.
The shape, material, quantity, arrangement, etc. of each member constituting the deployment device 8 may be appropriately selected.

FIG. 8 is a schematic perspective view of a moving mechanism of the folding device according to the present invention.
The folding device 6 is configured so that a linear guide 27 used for machine tools, article transport, etc. can be swung in the width direction of the filter cloth 3 by using a moving mechanism 16 that relatively moves the linear guide 27 in the axial direction by a feed screw mechanism 30. The moving mechanism 16 is composed of the linear guide 27, the feed screw mechanism 30, and a table body 32 that supports these.

Specifically, the linear guide 27 is composed of a pair of rails 26, 26 arranged in the width direction of the filter cloth 3, a pair of guide members 8, 8 that engage with each rail 26 and can slide on the rails 26 in the width direction, and a swinging part 21 that bridges each guide member 8 and can swing in the width direction.

The feed screw mechanism 30 is composed of a ball screw 22 provided in the width direction, a slider 29 that is screwed with the ball screw 22 and can be swung in the width direction by the rotation of the ball screw 22, a drive source 23 that rotates the ball screw 22, and a support part 34 that rotatably supports the ball screw 22. The slider 29 is connected to the oscillating part 21, which is a component of the linear guide 27, so that the oscillating part 21 can be swung in the width direction via the slider 29.

The swinging part 21 is connected to each component of the folding device 6 via a connecting member 24. The ball screw 22 is rotated forward and backward by the driving source 23 to swing the slider 29, thereby moving the folding device 6 in the width direction of the filter cloth 3 via the swinging part 21. In addition, the pressure rollers 12a, 12b, guide rollers 13a, 13b, and guide parts 14a, 14b that constitute the folding device 6 are each fixed to the connecting member 24 and fixed to the common swinging part 21 via the connecting member 24, so that they swing together.

The linear guide 27 and the feed screw mechanism 30 are supported by a table body 32. The table body 32 is composed of a support member 31 with an open center on which the pair of rails 26 of the linear guide 27 and the drive source 23 of the feed screw mechanism 30 are placed, and support legs 25 attached to the four corners of the bottom of the support member 31.

In this embodiment, the feed screw mechanism 30 is shown as the moving means, but known mechanisms such as a cylinder mechanism, a rack and pinion mechanism, a link mechanism, etc. can be used. The driving source 23 that rotates the ball screw 22 is not limited to hydraulic, mechanical, manual, etc. The configuration of the linear guide 26 is also not limited to the connecting positions of each member, such as the connecting position of the folding device 6 and the connecting member 24, and the connecting position of the slider 29 and the oscillating unit 21. In addition, the shape, material, arrangement, etc. of each member of the table body 32 and the oscillating unit 21 are also determined appropriately.

The belt press 1 of the present invention performs a sludge supplying process S1 in which sludge is supplied onto an endless filter cloth 3 that is freely slidably wrapped around a number of rollers 2..., a cloth folding process S3 in which the filter cloth 3 is folded back from both sides in the width direction toward the supply side and the folded back filter cloths 3 are overlapped to form a filtration space 5, a squeezing filtration process S4 in which the sludge in the filtration space 5 is squeezed and filtered, a cloth unfolding process S5 in which the folded back filter cloth 3 is unfolded, and a cake peeling process S6 in which a cake is peeled off from the unfolded filter cloth 3. In addition, in the cloth folding process S2, the folding device 6 is moved a predetermined width in any direction to shift the positions of the folds 10a, 10b formed on the folded back filter cloth 3.

<Folding position shifting step (S2)>
9, 10, 11, and 12 are plan views for explaining the folding position shifting step S2 according to the embodiment of the present invention.
9, 10, and 11 show how the folder is swung in the width direction, and Fig. 12 shows how the position of the folding portion shifts when the folder is swung. Fig. 9 corresponds to Fig. 12(a), Fig. 10 corresponds to Fig. 12(b), and Fig. 11 corresponds to Fig. 12(c).

FIG. 10 shows the filter cloth folded back evenly from both sides.
The pressure rollers 12a and 12b constituting the folding device 6 are disposed so that their centers are located on a center line that intersects with the axis of the guide roller 33. The distance in the width direction from the center line to the center of the pressure roller 12a and the distance in the width direction from the center line to the center of the pressure roller 12b are both zero.
In the following, all distances are measured in the width direction.

In addition, the guide rollers 13a and 13b are each installed at an equal distance from the center line. Similarly, the guide sections 14a and 14b are each installed at an equal distance from the center line. By positioning each component of the folding device 6 based on the center line, the filter cloth 3 can be folded back at any width from the left and right.

By positioning the folding device 6 as shown in FIG. 10, the width t1 of the folded surface 11a from the left side of the filter cloth 3 and the width t2 of the folded surface 11b from the right side are equal, as shown in FIG. 12(b). At this time, the distance from the formed fold 10a to the center line and the distance from the fold 10b to the center line are equal.

If the filter cloth continues to run in this state without shifting the folding position 6, it will repeatedly fold and unfold at the same location. This causes localized stress on the folding portions 10a and 10b, which can lead to tearing of the filter cloth. Therefore, in the present invention, the folding device 6 is forcibly moved a predetermined distance in any direction to shift the positions of the folding portions 10a and 10b while operating. This prevents stress from being concentrated on the folding portions 10a and 10b, and prevents early tearing of the filter cloth.
In addition, since the formation positions of the folding portions 10a, 10b are determined by the arrangement positions of the respective components constituting the folding device 6, when moving the respective components constituting the folding device 6 a predetermined width in any direction, the respective components constituting the folding device 6 are moved integrally.

FIG. 9 shows that the folder is pivoted leftward by a predetermined distance from the position shown in FIG.
Each member constituting the folding device 6 is swung to the left by a predetermined width. As a result, the centers of the pressure rollers 12a and 12b, which had a distance of 0 to the center line in Fig. 10, are now spaced a predetermined distance from the center. Also, the distance from the center to the center line of the left guide roller 13b is greater than the distance from the center to the center line of the right guide roller 13a. Similarly, the distance from the center to the center line of the left guide portion 14b is greater than the distance from the center to the center line of the right guide portion 14a.

By moving the folding device 6 a specified width to the left based on the center line, the filter cloth 3 guided by the guide roller 33 is pressed by the pressure roller 12b and guide rollers 13a, 13b that have moved to the left so that the right side is higher than the left side, and is folded back at the bottom of the guide sections 14a, 14b together with the upper filter cloth 3a guided from above via the pressure roller 12a.

At this time, the folds 10a and 10b formed have moved a certain distance to the left from the position shown in FIG. 12(b), as shown in FIG. 12(a), and the width t2 of the fold 11b is greater than the width t1 of the fold 11a. Also, the distance from the fold 10a to the center line is greater than the distance from the fold 10b to the center line.

FIG. 11 shows the folding device being swung rightward by a predetermined distance from the position shown in FIG.
The entire folding device 6 is swung to the right by a predetermined width. As a result, the centers of the pressure rollers 12a and 12b are spaced a predetermined width from the center line. Also, the distance from the center of the left guide roller 13b to the center line is smaller than the distance from the center of the right guide roller 13a to the center line. Similarly, the distance from the center of the left guide portion 14b to the center line is smaller than the distance from the center of the right guide portion 14a to the center line.

By moving the folding device 6 a specified width to the right based on the center line, the filter cloth 3 guided by the guide roller 33 is pressed by the pressure roller 12b and guide rollers 13a, 13b that have moved to the right so that the left side is higher than the right side, and is folded back at the bottom of the guide parts 14a, 14b together with the filter cloth 3 guided from above via the pressure roller 12a.

At this time, the folds 10a and 10b formed have moved a certain distance to the right from the position shown in FIG. 12(b), as shown in FIG. 12(c), and the width t2 of the fold 11b is smaller than the width t1 of the fold 11a. Also, the distance from the fold 10a to the center line is smaller than the distance from the fold 10b to the center line.

In this manner, by swinging the folding device 6 by a predetermined width in any direction, the positions of the folded portions 10a, 10b formed on the filter cloth 3 guided by the guide rollers 33 can be shifted.
When the folding device 6 is swung by a predetermined amount, the unfolding device 8 may also be moved in the same manner.

In this embodiment, the positions of the folded portions 10a, 10b may be shifted stepwise while the filter cloth is traveling, or may be shifted constantly. In the case of shifting stepwise, a predetermined time is set in advance, and the folding device 6 is moved after the predetermined time has elapsed to shift the positions of the folded portions 10a, 10b stepwise. Alternatively, a predetermined number of revolutions that the filter cloth 3 will make around the belt press 1 is set in advance, and the folding device 6 is moved after the predetermined number of revolutions is detected to shift the positions of the folded portions 10a, 10b stepwise. In the case of shifting constantly, the folding devices 6a, 6b are moved in the width direction of the filter cloth 3 while the filter cloth is traveling.
It should be noted that since it is sufficient to shift the turn-back position of the filter cloth 3 while the filter cloth is traveling, the timing of the shift can be appropriately selected.

The belt press folding method of the present invention can be used in a belt press that folds an endless filter cloth from both sides in the width direction to form a filtration space. By running the filter cloth while shifting the position of the folded part, it is possible to prevent localized stress from acting on the folded part and prevent the filter cloth from breaking early. This prevents the filter cloth from breaking and causing sludge to leak, and eliminates the need for repairs or replacement when the filter cloth breaks, thereby saving time and cost. In addition, the downtime required for maintenance is shortened, making it possible to continue efficient continuous dehydration operation. The device is also easily configured, so it can be easily applied to existing belt presses.

REFERENCE SIGNS LIST 1 Belt press 2 Roller 3 Filter cloth 5 Filtration space 6 Folding device 10a, 10b Folding section 12 Pressing roller 13 Guide roller 14 Guide section 16 Movement mechanism 21 Swinging section
S1 Sludge supply step S2 Filter cloth folding step S3 Squeezing filtration step S4 Filter cloth spreading step S5 Cake peeling step

Claims (3)

In a belt press which performs a sludge supplying step (S1) of supplying sludge onto an endless filter cloth (3) which is stretched around a plurality of rollers (2) so as to be capable of freely moving, a filter cloth folding step (S2) of folding the filter cloth (3) from both sides in the width direction toward the supply side and overlapping the folded filter cloths (3) to form a filtration space (5), a squeezing filtration step (S3) of squeezing and filtering the sludge in the filtration space (5), a filter cloth unfolding step (S4) of unfolding the folded filter cloth (3), and a cake peeling step (S5) of peeling a cake from the unfolded filter cloth (3),
In the filter cloth folding process (S2),
A method for folding a filter cloth in a belt press, comprising: oscillating a folding device (6) in the width direction of the filter cloth (3); guiding the filter cloth (3) to the folding device (6) that has been moved a predetermined width; and shifting the positions of the folds (10a), (10b) formed at both ends of the filtration space (5). 2. The method for folding a filter cloth using a belt press according to claim 1, characterized in that, in the filter cloth folding step (S2), a folding device (6) having a pressure roller (12), a guide roller (13), and a guide portion (14) is swung in the width direction of the filter cloth (3). 3. The method for folding a filter cloth using a belt press according to claim 1, wherein the folding device (6) is provided on a moving mechanism (16) having a swinging part (21) capable of swinging in the width direction of the filter cloth (3).

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